The present invention relates to power management in mobile communication devices in general and to reducing power consumption in wait-mode, when using non-sequential data format in a communication protocol.
Methods for reducing power consumption in wait mode are known in the art. U.S. Pat. No. 4,961,073, to Drapac et al., teaches a method which operates in a communication protocol, having a paging transmission which includes two parts. While receiving the first part of the paging transmission, its validation is detected. If the first part is determined valid, then, the second part of the paging transmission is received. Otherwise, the power is disconnected from the receiver.
U.S. Pat. No. 5,537,100, to Hallberg, describes a method and device for use in pagers, which decodes a conventional serial paging transmission, using a methodology of looking for a pattern of non-correlated bits. The method according to this patent compares a received word with the address of the receiver of the pager and counts non-correlated bits between them.
For example, in a communication protocol having a Bose-Chaudhuri-Hocquenghen (BCH) decoder which is able to correct up to two errors, if at least three non-correlated bits are detected, then the received word is determined not relevant and the device disables power to the receiver, thereby reducing power consumption.
Reference is now made to FIG. 1, which is a schematic illustration of code collation, known in the art. Bit sequence 100 is the mobile station identifier (MSI) number of a receiver and bit sequence 102 is a received string of bits which is attached to a paging transmission. Sequence 102 includes an ID section 104 and a channel coding section 106, used for error correction. A BCH decoder can correct up to one error in section 104 using section 106.
In the present example, there are two mismatches 110 and 112, between the received ID sequence and the MSI of the receiver. According to the prior art, if the number of mismatches is greater than the number of errors that can be corrected, then the received ID can be ignored. The reason being that even if the maximal number of errors in the received ID will be corrected using channel coding bits 106, there would still be at least one mismatch between the received ID and the MSI.
It will be appreciated by those skilled in the art that the above methods provide solutions for sequential data. Non sequential data can not be processed according to these methods. It will also be appreciated that in the art, there are no solutions to a situation when either the data or the channel coding bits are provided in a non-sequential format.
It is an object of the present invention to provide a novel method for reducing power consumption in wait-mode, when using non-sequential data format in communication protocol.
It is a further object of the present invention to provide a novel device for reducing power consumption in wait-mode, when using a non-sequential data format in communication protocol.
In accordance with one aspect of the present invention, there is thus provided a method for reducing power consumption of a receiver, having an identification number and receiving a portion of a hailing message in a non-sequential manner.
The hailing message includes a plurality of data lines and each data line includes an information portion and a channel coding portion.
The channel coding portion provides correction of a predetermined maximal number of errors of the information and the received portion of the hailing message includes the information portions of a plurality of the data lines. Accordingly, received portion of the hailing message contains at least a portion of the hailed identification numbers. The method includes the steps of:
detecting portions of the hailed identification numbers within the received portion,
comparing between the portions of the hailed identification numbers and the respective portion of the identification number, thereby detecting mismatches therebetween, and
terminating reception of the hailing message if the number of the detected mismatches, for each of the portions of one hailed identification numbers, exceeds the maximal number of errors.
In accordance with another aspect of the present invention, the method further includes the steps of:
receiving an additional portion of the hailing message,
combining the additional portion with the received portion, and
repeating from the step of detecting.
In accordance with a further aspect of the present invention, there is provided a device for reducing power consumption of a receiver, connected thereto. The receiver has an identification number and receives a portion of a hailing message in a non-sequential manner.
The hailing message includes a plurality of data lines, wherein each data line includes an information portion and a channel coding portion. The channel coding portion provides correction of a predetermined maximal number of errors of the information. The received portion of the hailing message includes the information portions of a plurality of the data lines thereby containing at least a portion of at least one hailed identification number.
The device includes a controller, connected to the receiver, a buffer, connected to the receiver, for temporarily storing the received portion of a hailing message, a storage unit, containing the identification number and a comparator, connected to the buffer, the storage unit and the controller, for comparing the portion of the at least one hailed identification number with the respective portion of the identification number.
The comparator provides the number of mismatches, between each portion of each hailed identification number and the respective portion of the identification number, to the controller.
The controller provides a power reduce command to the receiver, when all of the numbers of mismatches, exceed the predetermined maximal number of errors.
The buffer can further accumulate additional portions of the received portion of a hailing message.